Asymmetrical Tooth Defects Observed in Hypoplastic Primary Teeth and Amelogenesis Imperfecta: Case Reports
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PEDIATRIC DENTiSTRY/Copyright © 1987 by The American Academy of Pediatric Dentistry Volume 9 Number 2 CAS Asymmetrical tooth defects observed in hypoplastic primary teeth and amelogenesis imperfecta: case reports Anne L. Symons, MDS J.P. Gage, BDS, PhD, HDD, FDS, FRACDS Abstract Factors that may disturb ameloblasts and result in Tworare cases of asymmetricaltooth destruction affecting their producing hypoplastic enamel include genetic the primarydentition and1 case of hypoplastic,vertical striping causes, nutritional deficiency, maternal illnesses, birth X-linked amelogenesisimperfecta which affects the permanent injury, and trauma (Kreshover et al. 1958). dentition in an asymmetricalmanner, are presented. The etiology This paper presents 2 unusual cases of tooth de- of the conditionsare discussedwith respect to inheritance,pre- struction and 1 case of hypoplastic amelogenesis im- eruptiveand posteruptiveinfluences. The asymmetricalgross tooth destruction reported in the 2 primarydentitions maybe multi- perfecta and discusses the possible reasons for the factorial in origin but genetic influencescannot be excluded. atypical distribution of defects. Variations in the number and form of teeth Case 1 are, in general, genetically determined, but modifi- A 4-year-old Caucasian female was referred to cations may also arise as a result of a numberof other the pedodontic clinic for managementof gross enam- influences. For example, the absence of teeth such as el erosion and severe wear of the primary teeth on lateral incisors or third molars may be an inherited the left side. anomaly--as may other conditions such as amelo- The medical history revealed no significant or genesis imperfecta and dentinal dysplasia. On the relevant illnesses. The patient had not received any other hand, pre-eruptive influences such as systemic radiation treatment, was born full term, and was of illnesses or local trauma may result in alteration of average height and weight. The history of the preg- the tooth bud components during tooth formation. nancy and postnatal period was uneventful. No un- Dental structures generally are well protected usual oral habits were elicited and the diet was well from damaging influences during intrauterine life balanced with a moderate intake of sucrose, mainly but children with premature or traumatic births tend in liquid form. The patient resided in a nonfluori- to have a higher incidence of dental anomalies in the dated area and had not taken fluoride supplements. primary dentition (Rosenzweig and Sahar 1962). Kre- As an infant the child favored sleeping on her left shover et al. (1958) examined the prevalence of de- side. velopmental dental abnormalities in primary teeth The mother reported that the primary teeth in and concluded they were more common than pre- the left quadrant were stained, dull, and failed to viously thought. Microscopic examination of the teeth erupt completely. At the time of eruption they were of both jaws showed a prominent incremental line defective, with soft enamel which chipped easily, ex- extending over the incisal and occlusal portions of posing the dentinal surface. Maintaining good oral the deciduous anterior and posterior teeth. Rosen- hygiene around the affected teeth was difficult as the zweig and Sahar (1962) and Kreshover et al. (1958) gingivae were red, swollen, bled easily, and were found that children with hypoplastic teeth had a painful during brushing. The dentitions of the 2 male greater dmf rate than those without hypoplasia and siblings were unaffected, with minimal caries activ- suggested that hypoplastic teeth may be more sus- ity. The mother was edentulous and described her ceptible to dental caries than normally calcified teeth. own teeth as weak and thin with a tendency to crack 152 ASYMMETRICAL GROSS TOOTH DEFECTS: Symons and Gage FIG la. Gross tooth destruction and poor gingival health FIG lb. Teeth in the lower left quadrant were severely was evident in the left quadrant. decayed and gingival health was poor. The teeth in the right quadrant showed demineralization of the enamel in the gingival third. shortly after emergence. Consequently they were re- moved early. On examination the child appeared healthy, of Electrophoresis of the dentine collagen peptides normal height and weight with no detectable body was performed on primary teeth on the left side of asymmetry. The right dental quadrants seemed nor- the mouth. A piece of dentine from the exfoliated mal with teeth having reasonable crown height and lower left lateral incisor was crushed to a powder and good occlusion. The teeth in the left quadrants were dialysed with 24-hr changes of 0.5 M EDTA pH 7.4 severely worn, occlusal enamel was absent and ex- at 4°C until the atomic absorption of the extracts for posed carious dentine was evident on the primary calcium at 422.7 nm was minimal. The residue was canines and molars (Figs la, b). Loss of interarch dis- washed several times with distilled water, spun down, tance had occurred between the left buccal segments and lyophilized. due to wear and reduction in crown height (Fig 2). Ten mg of the freeze-dried residue was cleaved The gingivae on the left side were inflamed, swol- with cyanogen bromide (CNBr-substrate ratio 4:1) len, and associated with plaque deposits. in 70% formic acid (substrate concentration 10 mg/ Radiographs revealed bone loss around the pos- ml) for 4 hr at 40°C. At the completion of the reaction terior teeth on the left side, caries, absence of max- the mixture was diluted with 20 Vol of distilled water illary second premolars, and a poorly forming upper and freeze dried to remove both acid and CNBr. The right lateral incisor that appeared to be a peg lateral sample then was dissolved in 0.625 M Tris-HCl Buffer incisor (Figs 2, 3). containing 2% (W/V) SDS and loaded into the sample The treatment consisted of instructions in oral wells of a polyacrylamide gel. hygiene, dietary advice, systemic fluoride, and rou- At completion of the electrophoresis the gels were tine operative therapy. A stainless steel crown was stained with silver stain and then were scanned on placed on the maxillary left primary molar and after the light table of an ultra scan laser densitometer with caries removal glass ionomer restorations were placed a fixed wavelength of 633 nm. The densitometric pro- to protect the severely worn teeth. The oral hygiene files show that the collagen obtained was identical to improved but the gingivae on the left side remained that obtained from normal primary dentine. inflamed since the patient resisted thorough cleaning in this region. Case 2 The patient was recalled regularly and by age 7 A 2V2-year-old Caucasian female was referred to years was well motivated. Oral hygiene had im- the Children's Dental Clinic for management of gen- proved but she developed a preference for sweet eralized hypoplasia of the primary teeth. A medical snacks. The first permanent molars emerged in all history reported occasional ear infections which were quadrants and appeared free of any defects as were treated with antibiotic therapy. The patient had not the 2 lower central incisors (Figs 3a, b). The severely received any radiation therapy, was healthy, born at worn primary teeth were free from symptoms but full term, and was of average height and weight. The most of the protective glass ionomer cement resto- child resided in a nonfluoridated area and had not rations had been worn away. taken any fluoride supplements. The mother breast- PEDIATRIC DENTISTRY: June 1987/Vol. 9 No. 2 153 FIG 2. OPG radiograph showing absence of upper second FIG 3a. Upper quadrants 3 years after the initial appoint- molars and a poorly forming right lateral incisor. ment. The first permanent molars are erupting and are free of defects. fed her daughter until the age of 14 months, per- mitting the child to fall asleep during feeding. No An asymmetry in the distribution of this genetic de- particular side was favored during sleep. Sucrose was fect was observed (Fig 6). This patient also has a con- ingested, mainly in the form of fruit juices (they were genitally missing maxillary right lateral incisor. The slowly withdrawn after the initial dental appoint- medical history was not significant. ment in the pedodontic clinic). On examination, most primary teeth were present, the upper left primary Discussion second molar was erupted and the lower left primary Asymmetrical gross tooth destruction is unusual second molar was erupting. Minimal plaque was pres- and may be caused by a variety of conditions. In the ent and the gingivae appeared healthy. Smooth sur- patients in this report, the structure of the teeth may face, early carious lesions were evident on the buccal have been affected at various stages due to genetic surfaces of most teeth and the teeth on the left side influences, pre-eruptive, or posteruptive factors which were abraded. Preventive treatment was instigated resulted in the asymmetrical distribution of tooth de- and the mother was instructed in brushing the child's struction. teeth and given dietary advice. The patient was re- As would be expected with a genetic disorder, called at three monthly intervals. The dentitions of the condition should affect all quadrants equally. The two older brothers were unaffected, with minimal first 2 cases show severe tooth destruction unilaterally caries activity and no other members of the family appeared to be similarly affected. At age 3'/2 years the teeth on the left side showed increased wear, while teeth on the right side were minimally abraded (Figs 4a, b). Buccal lesions were present on all teeth, with the left side more severely affected (Figs 5a, b). While caries was not detected on the occlusal surfaces of the left molars, occlusal wear was evident with dentine exposed on the first molars. The enamel covering the occlusal surfaces of the sec- ond molars on the left side was flecked and worn (Fig 4b).